Hunt, L. A., van

The immature stages of 14 species in the subfamily Pierinae out of the 28 species of Pieridae in Sri Lanka and their larval food plants are presented. Ten species including three endemic subspecies are documented for the first time. The remaining four species including one endemic subspecies are compared to prior descriptions and additional observations are presented. Previously reported larval food plants are confirmed and new ones identified. This study provides some base information needed for conservation management programs for butterflies in Sri Lanka and for further studies on the biology of these species. Identification notes are given for Capparis zeylanica and Capparis brevispina, two important larval food plants, which have frequently been misidentified in the literature.

Postanthesis carbon dioxide exchange and transpiration rates of flag and penultimate leaves of five spring-wheat (Triticum aestivum L. emend. Thell.) cultivars were measured from complete flag-leaf expansion to senescence. Leaf nitrogen contents were determined from anthesis to maturity. Both the absolute level of and the time-related decline of the carbon dioxide exchange rate varied among the cultivars. The flag-leaf carbon dioxide exchange rate decreased steadily throughout for one cultivar and slowly for a varying period and then rapidly for most others. The penultimate-leaf carbon dioxide exchange rate decreased throughout with one cultivar but did not decline in the period from 1 to 3 weeks postanthesis in others. The transpiration rate peaked at or near anthesis for the flag leaves and then either declined or fluctuated around the peak value for 3 weeks. The penultimate-leaf transpiration rate increased to a second peak late in ontogeny for most genotypes. In general, the time course of the transpiration rate matched that of the carbon dioxide exchange rate, but the transpiration rate at a specific carbon dioxide exchange rate was lower for penultimate than for flag leaves. The carbon dioxide exchange rate was linearly related to leaf nitrogen content, with the same regression applying for both flag and penultimate leaves; regressions were similar for all genotypes. There were no marked deviations from the overall carbon dioxide exchange rate – nitrogen regression that could be indicative of a "sink" influence on the activity of photosynthetic enzymes.

Morphological variability among four species of Mycalesis in Sri Lanka that are difficult to discriminate due to their morphological similarity was investigated to identify characters that distinguish species more accurately. Using traditional morphometrics, 90 variables from the wing, forelegs and genitalia of M. perseus typhlus, M. mineus polydecta, M. subdita and M. rama were measured and analysed. A set of 19 characters of the wing, male genitalia and forelegs were identified to discriminate species. Results of the analysis showed that male specimens were discriminated with nine wing characters and five characters of genitalia. Females could be discriminated with three wing characters and two foreleg characters. Male specimens of M. p. typhlus and M. m. polydecta showed the greatest morphological differentiation, while females of M. subdita and M. rama were the most similar species. These results were used to improve the currently available identification key. Two instances of possible hybridisation were discovered: one between M. p. typhlus and M. m. polydecta and the other between M. p. typhlus and M. subdita. Hence, the species of Mycalesis, particularly M. p. typhlus, M. m. polydecta and M. subdita may not be strictly reproductively isolated in Sri Lanka. Preliminary comparisons of M. p. typhlus in Sri Lanka with M. p. tabitha of India indicated that the Sri Lankan subspecies is unlikely to be a synonym.

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